1. Field of the Invention
This invention relates to a switch, and more particularly to a wall switch with a current control safety module, designed both for safety concern and for low maintenance demand.
2. Description of Prior Art
Wall switches are used commonly with lighting devices, hanging fans, or other electronic devices. Nevertheless, most conventional wall switches are not designed well enough to be protected from overload in current, causing safety problems. For instances, lighting devices are in general used for some sustained period of time; high temperature due to bad design in contact or low quality in conductive wires may cause the neighborhood of the contact or conductive wires to melt, resulting in a short circuit or a fire.
To look out for safety concern and outer appearance as well in lighting devices, most inventions resort to capacitors, printing circuit boards, etc. along with dozens of thin conductive wires, seriously effecting the efficiency of hear dissipation, damaging conductive wires, and possibly causing a short circuit.
For wall switches connected with fans or other electronic devices, a short circuit occurs when motor coils fail to cut off an overloaded current, which results when a fan motor is not operating smoothly.
Some wall switches are equipped with a safety module, comprising essentially a metal piece which deforms when heated and is thus expected to break the circuit. A disadvantage associated with such an invention lies in the fact that a variety of unexpected deformations may occur in the metal piece when heated, as a result, currents may still go through the metal piece despite its deformation. The second disadvantage of using a metal piece as a current controller in a circuit is the inconvenience in the replacement of a deformed metal piece, requiring a higher maintenance cost.
It is the goal of this invention to provide feasible solutions for problems discussed above. In particular, the present invention arises to solve some defects encountered in a prior art, stated in details below.
FIGS. 7 and 8 show a conventional wall switch, comprising mainly a bottom seat 1, two conductors 2 and 3, a press button device 4, and a top cover 5. Two compartments 11 and 12 are defined within the bottom seat 1 for receiving the conductor 2 and 3, respectively. Two wire through-channels 111 and 121 are configured under the compartments 11 and 12, respectively. Two separate external wires run though wire through-channels 111 and 121. The conductor 2 and 3 are separated by a partition space A, contacting each other; the partition space A stands in between the two opposing walls partitioning the two compartments of 11 and 12.
A silver alloy first contact 21 is disposed on the conductor 2, facing toward the partition space A. An extension 31 extends from the lower end of the conductor 3 towards the partition space A. An upside-down V-like ridge 311 protrudes from the extension 31.
The press button device 4 has a press block 41, a spiral spring 42, and a U-like conductors-assembly 43. The press block 41 is pivotally installed on the top cover 5. Underneath of the press block 41 is configured with a spring sleeve 411 to receive the top end of the spiral spring 42. The U-like conductors-assembly 43 stands in the partition space A for engaging with the lower end of the spiral spring 42, with its bottom floor 431 concave inwards, corresponding to the upside-down V-like ridge 311 (of the extension 31), as shown in FIGS. 7 and 8.
A silver alloy second contact 432 is disposed on one side of the U-like conductors-assembly 43 in a location to correspond to the silver alloy first contact 21 (of the conductor 2). FIG. 7 shows the switch in an OFF mode since there is no contact between the silver alloy first contact 21 and the silver alloy second contact 432. FIG. 8 shows the switch in an ON mode: when the press block 41 shifts, the spiral spring 42 moves the conductor 43 in a way that the silver alloy first contact 21 (of the conductor 2) meets the silver alloy second contact 432 (of the conductor 43).
The top cover 5 has a central opening to receive the press block 41 (of the press button device 4). The top cover 5 engages with the bottom seat 1 via fixing legs 52 thereof.
Having discussed a prior art close to the present invention, we proceed to detailed descriptions of the present invention and its patentable characteristics.